Now, this is just a proof of concept, but it could fairly easily be turned into a count down clock, or dynamically incrementing "total donations" type display. To show this functionality, I've added a reset to start the clock at 12:00;00 am, making it flip forward to the current time.

As with the other CSS3 experiments, it currently only works in Firefox, Google Chrome, and Safari (which loses the rounded corners due to an interaction bug with transform-origin and border radius) UPDATE and Opera 10.5. One the nice thing about this experiment, as opposed to the other two, is that the clock still works in IE, even though the flip animation is missing.